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The formation of nanocrystalline Si films as a result of rapid thermal annealing of silicon-on-insulator structures implanted with high doses of H[sup +] ions is studied. It is ascertained that the process of formation of Si nanocrystals is active even at temperatures of 300–400°C and is controlled by the hydrogen content in the silicon film and by the duration of annealing. It is concluded that the formation of nuclei of the crystalline phase occurs in silicon islands surrounded by microvoids and is caused by the ordering of Si–Si bonds in the course of release of hydrogen from the bound state. It is important that microvoids do not coalesce at temperatures up to ∼900°C in conditions of rapid thermal annealing. It is found that synthesized films exhibit luminescence in the green–orange region of the spectrum at room temperature. © 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

Current–voltage characteristics and spectral dependences of photovoltage are investigated at T = 4.2 and 300 K in stress-free structures with germanium quantum dots (QDs) in the GaAs/ZnSe/QD–Ge/ZnSe/Al system. The “Coulomb staircase” type features in the current–voltage characteristic observed at room temperature without illumination are due to the Coulomb interaction of electrons in resonant tunneling through intrinsic levels in QDs. The features in the photovoltage spectra are related to the absorption of radiation in the system of discrete levels of QDs. An energy band diagram of the structure is constructed based on the experimental data. © 2003 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]